Roller cutter mounting



March 1, 1938. J. B. RAGSDALE ROLLER CUTTER- MOUNTING Filed June 2, 1936 g I? v 2 z Lwwwwww ww #1 w MG 2 w? I Patented Mar. 1,? 1938 I UNITED STATES.

2,109,909 e ROLLER corms MOUNTING John B. Ragsdaie, Whittier, CaliL, assignmto Globe Oil Tools Company, Los Nietos, OaliL, a

corporation of Callfo Application June 2, 1936, Serial No. 83,054

15 Claims.

This invention relates to well drilling tools and relates more particularly to well drilling tools embodying roller cuttersii; A general object of this invention is to provide a strong, effective and particularly dependable mounting for a roller cutter of a well drilling tool.

When a removable shaft or pin is employed as a support for a roller cutter of a well drilling tool the pin must be very securely locked or held in place to prevent its loss and the loss of the cutter. The threading of such a cutter supporting pin in a particular direct-ionso that rotation of the cutter tends to tighten the threads has been found to be insuificient to prevent the loss of the cutter and pin. In instances where the pin is not securely locked against rotation the torque on the pin resulting from rotation of the cutter sometimes tightens the threads to the extent that they shear or become distorted and do not hold securely. The vibration stresses set up in a cutter supporting pin are very great and often cause the pin to unthread and become lost even though it is threaded in to be tightened by the torque resulting from rotation of the cutter.

Another object of this invention is to provide a mounting for a'roller cutter of a well drilling tool which mounting embodies a threaded cutter supporting pin positively locked against rotation so that itcannot become lostfstrained, stripped or loosened during operation of the tool in the well. 7

Another object of thisinvention is toprovide a mounting for a rotatable roller cutter including' a threaded pin supporting the cutter and very simple yet dependable means for locking the pin against rotation in either direction so that its threads cannot be strained or sheared and so that the pin cannot become unthreaded.

Another object of this invention is to provide a roller cutter mounting embodying a threaded-in cutter supporting pin and means for positively holding the pin against rotation in both directions, which means does not necessitate the addition or employment of set screws, lock pins, cotter keys or similar partsthat may become lost or displaced.

A further object of this invention is "to providea cutter mounting of the character mentioned that is simple and inexpensive and in which the inclusion of the means for locking the pin against rotation does not'materially add to the cost or size of the mounting. A

The various objects and features of my invention will be fully understood from the following detailed description of a typical preferred form one of the cutter assemblies and mountings illus-.

trating the shape or condition of the pin prior to being locked in place.

The improved cutter mounting of the present invention may be embodied in well drilling tools 15 I of various types and constructions and may be employed in roller well bits as well as roller well core drills. In the following detailed disclosure I will describe .a typical form of the invention embodied in a more or less typical form of well core drill, it being understood that the invention. is not to be construed as limited or restricted to the specific form or application about to be described.

The core drill illustrated in the drawing includes a shoe or body In threaded to the lower end of a core barrelB. The body I0 is tubular having'a central longitudinal opening H for receiving the core and admitting itto the barrel well as the particular inner cutters C illustrated.

In the bit or core drill structure illustrated the inner and outer walls l3 and I3, respectively, of the recesses l2 are inclined downwardly and inwardly with respect to the central vertical axis of the tool. A projecting boss I4 is provided 45 i on the inner wall l3 of each recess l2 and pre-- sents a downwardly and inwardly inclined surface l5 substantially parallel with the opposing outer recess wall l3. The portions of the body III at or defining the outer walls of the recesses 5 [2 may be termed legs L while the portion of the body It! at the inner sides of the recesses I! may be termed a body wall W. The lower outer corners of the legs L are rounded or bevelled as illustrated in the drawing. A flat downwardly facing shoulder 15 is provided on each leg L at the lower end of its.wall l3. A similar downwardly facing fiat shoulder I1 is provided at the lower end or face of each boss 14. Passages or ports l8 extend downwardly through the body l3 to discharge the circulation fluid into the recesses l2. 1

The roller cutters C are substantially cylindrical and are each provided with a central 1ongitudinal opening 19. A socket or counterbore 23 is provided in each cutter C at the inner end of its opening 19. The outer ends of the cutters C may be flat and normal. Suitable cutting teeth 2| are provided in the peripheries of the cutters C to act on the earth formation. I

The mounting means of the present invention for supporting or mounting the two cutters C of the typical bit illustrated may be identical and I will proceed with a detailed description equally applicable to both mountings.

The cutter mounting of the present inven-v tion includes, generally, a threaded shaft or pin 25, means 28 for securing the pin against rotation, a suitable anti-friction bearing 21 rotatably supporting the cutter C on the pin 25 and non-rotatable washers 23 and 23 on the pin 25 at opposite ends of the cutter C.

The cutter supporting-pin 25 in addition toly normal to the walls l3 and I3 and the surface l5. In accordance with the invention the cutter supporting pin 25 is passed inwardly through the openings 34 to have its portion 3| threaded in the opening 33. The threaded portion 3| of the pin 25 is preferably of less diameter than the major portion 33 to provide the pin with an annular inwardly facing shoulder 35. The shoulder 35 is spaced outwardly some distance from the surface l5 of the boss l4 to leave a space for receiving the washer 23 to be hereinafter described. The portion 3l of the pin 25 may be threaded through the entire length of the opening 33 and the inner extremity of thepin 25 is ground or cut away to beflush with the wall of the opening II. The head 32 of the pin 25 is received inthe opening 34, the opening 34 being enlarged or provided with a counterbore to properly receive. the head 32. receiving socket 35 is provided in the head 32 to facilitate theturning or threading of the pin 25.-

The head 32 may be cylindrical in its general configuration to conform-to the opening 34. In the preferred construction a depression 53 is provided in .the outer end of the head 32. The depression 53 preferably occupies a substantial portion of the outer end of the head 32.

The means 23 for holding the pin 25 against rotation is an important feature of the invention. The means 25 operates to definitely secure the pin 25 against rotation in both directions and thus prevent, unthreading of the pin or straining and shearing of its thread. The means 25 includes or provides a notch 31 in the body [3. Where the pin 25 is inserted inwardly through the open-- ing 34 the notch 31 is preferably located to com- A polygonal wrench municate with the outer end of the opening 34. The notch 31 may be in the form of a vertical or longitudinally extending groove in the outer side of the leg L. When the notch 31 is of this configuration its lower end is in communication with the opening 34.

The means 26 includes an extension, tab or lug 38 on the head 32 cooperating with the notch 31. In accordance with the invention the lug 33 is an integral part of the head 32. The ing 33 is formed or provided by hammering or peening over an edge portion of the head 32. This forming or providing of the lug 38 is, of course, performed subsequent to the insertion and mounting of the cutter C, the pin 25 and the other elements of the cutter assembly. As illustrated in Fig. 3 of the drawing, the pin head 32 is proportioned to project some distance beyond the outer surface of the leg L when the pin 25 is fully threaded in place. The lug 38 is readily formed or provided by striking or hammering the projecting portion of the head 32 to distort it into the notch 31. The depression 53 is provided to facilitate the ready forming or peeningover of the lug 38. The lug 33 rather closely fits the lower portion of the notch 31 so that there is no play or possibility of movement of the pin 33 in either direction about its axis. The forming or peening of the lug 33 as just described removes or eliminates the projection portion of the head 32 so that the upper outer portion of the head 32 may be substantially flush with the outer surface of the leg L.

In accordance with the broader principles of the invention any suitable form of anti-friction bearing means may be provided for supporting the cutter C on the pin 25. In the typical case illustrated in the drawing the anti-friction bearing 21 comprises amultiplicity of rollers 33 in the opening I 9 of the cutter C, the rollers 39 of course bear on the major portion 33-.of the pin 25 to support the cutter C for free rotation on the pin.

The outer ends of the rollers 38 occur at or adja ends of the rollers'33 occur at or adjacent the bottom wall of the counterbore 23.

The washers 28 and 23 surround the pin 25 at the opposite ends of the cutter C to receive the end thrusts from the cutter and to prevent the wearing of the body l3 dueto rotation of the cutter. The washer 23 fits in or is received in the counterbore 23 to have suitable clearance'with its peripheral wall and to bear on or cooperate with its bottom wall. The washer 23 bears against the surface I5 of the boss 14 for the transmission of end thrusts to the body l3. In accordance with the invention the washer 23 has an extension or lug 43 projecting inwardly toward the central axis of the tool. The lug 43 cooperates with the shoulder 11 to hold the washer 23 against rotation. The annular shoulder 35 of the pin 25 may engage the inner side of the washer 23 whereby the washer is clamped between the shoulder 35 and the surface l5 of the boss l4. It will -be noted that the counterbore 23 of the cutter C receives the washer 23 and its lug 43 so that the washer cannot engage the core. The socket or counterbore 23 has a depth greater than the width of the washer 23 so that it receives a portion of the boss l4. thereby allowing the wall W, or the wall W and its boss l4, to have ample stock or wall thickness for the threaded end portion 3| of the pin 25 without thickening the entire body wall W.

The washer 23 has flat opposite faces or sides cutter for cooperating with the outer end of the C and for bearing on the outer wall l3 0! the recess l2. The washer 29 is provided with an extension or lug 4| projecting outwardly at its lower portion to cooperate with the shoulder l6. The cooperation of the lug 46 with the shoulder l6 positively holds the, washer 29 against rotation. Itwill be observed that the washers 28 and 29 formed and mounted as just described limit the end movement or play of the rollers 39. v The improved cutter mounting of the present invention is strong and dependable and may be embodied in a well tool without necessitating the addition of heavy body walls, cotter .keys, set screws or similar parts. The lug 38 may be easily and quickly formed following. the assembly'of the parts and its provision does not add to the cost of the mounting. The lug 38 being hammered or peened into the notch 31 closely fits the notch to positively prevent turning of the pin 25 in both directions and to prevent all rotary movement of the pin. The pin'25 may be properly tightened in prior to the forming of the lug 38 to form a strong link or connecting tie between the body wall W and the leg L. Following this tightening in of the screw 25 the forming of the lug 38 by peening or hammering locksthe pin in its tightened in position. Thus the lug 38 looks the cutter supporting pin 25 against rotation in both directions to prevent unthreading of the pin, straining or shearing of the' threads of the pin and the opening 33 by'torque on the pin and prevents loosening of the pin so that it continues to form a connecting tie between the leg L and the wall W. The pin 25 does not become loosened or displaced during the operation of the tool and the cutter C, the washers 28 and 29 and the rollers 39 are definitely held against loss in the well.

Having described only atypical preferred form and application of my invention I do not wish to be limited or restricted to the specific details herein set forth, but wish to reserve to myself any variations or modifications that may fall within the scope of the following claims.

. Having described my invention, I claim:

1. In a well drilling tool, a body having a recess and aligned openings joining the recess, a pin inserted through one opening and threaded in the other opening to extend through the recess, a rotatable cutter carried by the pin, and means holding the pin against turning comprising a peened-over part on the pin cooperating with the body.

2. In a well drilling tool, abody having a recess and an opening joining the recess, a threaded pin carried. in the opening and extending into the recess, a rotatable cutter in the recess carried by the pin, and apeened-over part on the pin cooperating with the body to hold the pin against rotation.

3. In a well drilling tool, a body havinga recess, an opening joining the recess, and a preformed notch, a pin threaded in the opening and extending through the recess, an extension on the pin cooperating with the notch to hold the pin against rotation, and a cutter in the recess rotatable on the pin.

4. In a well drilling tool, a body having anopening and a shoulder at one end of the opening. a threaded pin carried in the opening, an

opening and a shoulder atone end of the opening, a threaded pin carried in'the opening, a head on the pin,'a peened-over lug on the head cooperating with the shoulder to hold the pin against rotation, and a rotatable cutter carried by the pin.

6. In a well drilling tool, a body having an opening and a preformed'notch'at an end of the opening, a threaded pin extending through the opening,-a part of the pin peened into the, notch to hold the pin against rotation, and a rotatable cutter carried by the pin.

7. In a well drilling tool, a body having an opening and a preformed notch at an end or the opening, a threaded pin extending through the opening, a head on the pin, a part on the head peened into the notch to hold the pin against turning, and a rotatable cutter carried by the pin.

8. Ina well drilling tool, a body having a recess and aligned openings joining the recess, a

pin inserted-through one opening and having an end portion threaded in .the other opening and a head on its other end cooperating with the body whereby the pin ties together the body portions at opposite sides of the recess, a part on the pin peened over to cooperate with the body to prevent turning of the pin.

9. In a well drilling tool, a body having a recess, aligned openings joining the recess and a preformed notch at the outer end of one of the openings, a pin entered through the said opening and threaded in the other opening, a head on the pin cooperating with the body whereby the pin ties together the portions of the body at opposite sides of the recess, a part on the head peened in the notch to hold the pin against rotarotatable cutter on the pin within the recess,

wa whers on the pin at opposite ends of the cutter, and lugs on the washers cooperating with-the body to hold the washers against rotation.

11. In a well drill, a tubular body having a recess in its wall open at its lower end, a transverse opening intersecting the recess, and a preformed notch at the outer end of the opening, a pin passed inwardly through the opening and threaded in the opening at the inner side of the recess, a head on the outer" end of the pin cooperating with the body whereby the pin ties together the portions of the body at the inner and outer sides of the recess, a lug on the head cooperating with the notch to hold the pin against rotation, and a rotatable cutter in the recess carried by the pin. I

12. In a well drilling tool, a body having an opening and a notch atan end of the opening, a threaded pin extending thr ugh the opening, a head on the pin having a depression at its outer end, a part on the head peened into the notch to hold the pin against turning, and a rotatable cutter carried by the pin.-

13. In a well bit, a support having an opening, a cutter carrying pin having a portion received in the opening, and a part on the pin peened into a part of the opening to lock the pin against loss.

14. In a well bit, a support having an opening, a. cutter carrying screw received in the opening, and a part on the screw peened into an enlarged portion of the opening to prevent unthreading of the screw.

15. a. well drilling tool. two parts, one a body having an opening, theother a threaded pin in I the opening, a cutter supported by the pin, rind a peened-over portion on one of said parts co the pin against unthreading.

JOHN B. RAGSDALE.

, operating with the other of parts to hold 

